A bronze cast of the Tyrannosaurus rex skeleton known as the Wankel T.rex. Photo courtesy Museum of the Rockies.

Hold on to your butts*: The Smithsonian’s National Museum of Natural History is acquiring its first full Tyrannosaurus rex skeleton.

The museum reached an agreement with the U.S. Army Corps of Engineers to loan the skeleton, one of the most complete ever discovered, for 50 years, according to a statement from the Smithsonian. The T. rex will be displayed in the Natural History museum’s new dinosaur hall, set to open in 2019.

The Wankel T. rex, as its known because of its discoverer Kathy Wankel, was excavated between 1989 and 1990 from federal land near the Fort Peck Reservoir in Montana. It was housed at the Museum of the Rockies in Bozeman from 1990 to 2011.

The National Museum of Natural History’s new dinosaur hall was funded with a $35 million donation from conservative rich person David Koch. This was the largest single gift in the Smithsonian’s history.

*Note: This is a line from the film Jurassic Park. DCist does not require anyone to hold on to any body part while reading this post.